Coated or impregnated paper product and method of making same



. closures therefor.-

wax. It has been found that by the use of the com- Patented Aug.26, l941 REGNATED PAPER PD- UC'E AND METHOD OF G Frederick Shurley, Salt Lake City, Utah, assignor to Crown Cork & Seal Qompany, inc" Baltimore, Met, a corporation oi New York No Drawing. Application April 1,. 1936,

Serial No. 72,207

6 Claims.

i 'i'his invention relates toa composition of matter which may be applied to paper or paper-like materials and has particular application asa coating for, or ingredient of, paper employed in making receptacles adapted to contain milk, and The'invention also relates to the method of preparing and applying this composition and the resulting material.

It has been found that. when paper or like material is subjected to the action of mus, the' casein in the latter will react with the paper resulting in the formation of a gummy, adhesivelike substance. This is always objectionable and particularly so since'it causes paper milk bottle caps to stick, tightly to the tops of the bottles, or other containers. The sticking or gumming of the inner surface of the caps results in tearing of the paper'when the cap is removed and prevents reuse of the caps to again cover the product in the container.

Various coatings, as-for example, paraflin and other waxes, have been heretofore used in an attempt to overcome this condition, but have not met with success, owing to an objectionable reaction between the casein of the milk and the position herein described. either as an ingredient of the paper or as a coating for the paper,

the above mentioned difliculties may be overcome.

illustrative embodiment of the invention the production of such articles will be described.

In the manufacture of paper milk bottle caps,

.cap linings, or paper containers, the paper may be first coated with a composition having the following formula:

Water gallons" 1 I Glyceryl mono-stearate ounc -4 Glycerol do 2 The .water acts as the carrier or base for the other ingredients. The glyceryl mono-stearate contributes the lubricating, plasticizing, bonding,- and casein resisting properties of the product, and the glycerol acts as an emulsifier and makes possible the production of acolorless, spreadable,

' penetrating, and non-staining product.

Qther advantages of 1 this composition over waxes and similar coatings reside in its enhanced lubricating power which prevents the paper from. breaking as frequently occurs in the dry die forming out of tops and bottoms of cylindrical containers, drinking cups, cardboard pie plates. and similar articles from the blank material. In addition, the composition bodies and revitalizes the paper, sothat its shape is permanently retained. A particular advantage of the composition is that it does not stain paper and may be successfully used on substantially any typeof paper.

The composition reduces the surface tension of'all water soluble materials, and because of its penetration into the fibre,it makes the paper more flexible. It also aids the dispersion of pigments, dyestuiis and coloring matter, causing them to spread more evenly and uniformly, and

insuring a proper penetration. Furthermore, the

composition is not toxic or in any way injurious to food products and has no disagreeable odor.

It will be understood that the invention is not confined to the treatment of materials which are to be used for containers or closures, but as an Although not essential, it may be desirable to add to the above composition aboutlO grams of Lohrinol, (the trade name of aproduct consisting of sodium lauryl sulphonate sold by Glyco Products 00.. Inc.) which will tend to increase the penetratingand' spreading qualities of the composition and about 5 grams of benzoate of soda which will act as a preservative.

The above, composition is prepared by heating the water toapproximately 55 0., adding the Lohrinol, (if used) and stirring until solution is efi'ected. The glycerol is then added, and following the addition of the glycerol. the glyceryl mono-stearate is added. The preservative .(if

used), may be added before or with the-addition of the glyceryl mono-stearate. The mixture is stirred during the'addition of these ingredicuts, and stirring is continued until the ingredients have emulsified. The temperature is maintained at approximately 55 C., until the emulsification' has been completed. after which the heat is removed. During the subsequent cooling, the stirring is continued to prevent separation, and a white product of butter-like consistency will result.

In preparing the composition, I sometimes find it desirable to add about 2 grams of vanillin or other flavoring material to give the otherwise odorless product a pleasant aroma.

I have referred above to the preferred quantitles of ingredients used in preparing this composition, but I find that from 3 to 8 ounces of the glycerylmonostearate and from 2 to 4 ounces of the glycerol, when added to 1 gallon of water,

.wm give satisfactory results. Obviously, the

quantities of the non-essential ingredients, such as LohrinoY' and the preservative, may be varied within wide limits.

In some cases, it is preferable to incorporate the composition in the paper during the manufacture of the latter by mixing it in suitable proportions with the paper pulp prior to the drawing or screening of the paper. It has been found that the composition when so used bonds very effectively in the paper.

Where the product is used in connection with containers for food it is usually essential that it be odorless or that such odor as may be present he a pleasant one and the above described composition meets this requirement. However, when the presence or absence of an odor is immaterial it is possible and may be desirable to use, in

place of the glyceryl mono-stearate, equal quantities of glyceryi di-stearate, glyceryl tri-stearate, triethanolamine stearate or trihydroxyethylamine stearate (sold by Glyco Products 00., Inc.)

The above described composition may be used in the preparation of ceramic products as a temporary binder for molded clay articles such as 'firebricks, prior to fusing, .flring or baking, en-

abling the clays to be molded without crumbling. The advantages of the use of this composition for such a purpose are dueto its water dispersability, andthe fact that it, being completely organic, leaves no residue on firing. The quantity which is added is not critical, but is generally determined merely by adding the composition to the clay with mixing until the desired plastic consistency is obtained.

The composition also serves as an excellent binder for abrasive materials in the manufacture of solid articles, such as abrasive wheels, due to its water dispersability and its completely organic nature. It may be compounded with abrasive material in any convenient proportions to form a plastic moldable article and upon heating. firing or fusing the article, the binder volatilizes and completely disappears.

I claim: I

1. Paper treated with a composition comprising glycerol and a substance selected from the roup consisting of the glyceryl stearates, glycol stearates, triethanolamine stearate and trihydroxyethylamine stearate.

2. Paper treated with a composition comprising glycerol and glyceryl mono-stearates.

3. A method of treating paper which comprises applying thereto a composition comprising glycerol, a substance selected from the group consisting of the glyceryl stearates, glycol stearates, triethanolamine stearate and trihydroxyethylamine stearate, and water and thereafter drying.

4. Paper treated with a composition comprising glycerol, sodium lauryl sulphonate and a substance selected from the group consisting of the giyceryl stearates, glycol stearates, triethanolamine stearate and trihydroxyethylamine stear-' mmmrucx SI-IURIEY. 

